Left Ventricular Dyssynchrony by Phase Analysis is a Predictor of Cardiovascular Outcome in Patients with LV Dysfunction

Aims We hypothesize that detection of left ventricular dyssynchrony by phase analysis; a)is analogous but more reproducible than with echocardiography b)is predictive of outcome independent of extent of infarction c)is predictive of cardiovascular outcomes after cardiac resynchronization therapy (CRT). d)and the relationship between dyssynchrony and outcomes is continuous. Background A considerable percentage of patients do not derive benefit from CRT. Accordingly, there has been an increasing interest in evaluating dyssynchrony as a tool to better stratify patients. Reproducibility remains the major problem of echocardiography. Phase analysis of gated SPECT is an important alternative. The only published survival data with phase analysis is from a small pilot study from our group of patients with ICDs in whom standard deviation was predictive of mortality and appropriate ICD therapy. Although the mean and median values for dyssynchrony indices are known in healthy patients and those with cardiomyopathy, it is not clear which parameter and what cut-off value to use. Our current research project aims at answering whether dyssynchrony indices are predictor of cardiac outcomes in patients with CRT. Research design Patient selection: 1.Patients with cardiomyopathy and ejection fraction